The overall objective of the total project is elucidation of the pathogenic factors in acne vulgaris so that preventive measures and more effective therapy can be formulated. Toward this objective we have planned: to determine the reasons for, and the significance of, the low levels of linoleic acid in the skin surface lipids of acne patients; to investigate the biochemistry and physiology of lipid synthesis and excretion in human sebaceous glands in vivo; to use in vitro techniques to determine the identify of substrates used for lipid synthesis in sebaceous glands and the biochemical pathways by which the unique sebaceous lipids are produced; to extend our clinical studies of therapeutic procedures for acne which act by reducing the rate of sebum production or the degree of bacterial hydrolysis of sebum triglycerides; to investigate the mechanisms involved in the action of 13-cis retinoic acid on sebaceous gland function.